TOPIC: 1963 Johnson 28hp Seahorse not pumping water

Hi Guys,
I'm new to classic boating and need a hand. My son and I are working on a 16' fiberglass Duo. I picked up an awesome running
1963 Johnson 28hp outboard for it. The son of the original owner said it was always a reliable and great running motor that his
dad took care of. From sitting so long he suggested it probably wouldn't hurt to put in a fresh impeller. As is, it was piddling out.
The old impeller had a couple broken fins. We installed a new one and can't get any discharge. We triple checked installation and lining everything up. i checked and blew out all passageways, no discharge. i can't believe it's anything major but I don't want to screw up this sweet old motor for my ignorance.

Running it in a pail? If so perhaps not in enough water. Are able to test it on the boat in a lake?

We've been using a trash can filled to the top. Water level is a few inches above the intake.

Thank you for your response. Put the lower end back together and filled the barrel up higher than usual. The motor pumps GREAT!

Had the same issue with my 65 33hp seahorse a few years ago...

The pumps are not self priming. You have to have the water line in the tank well above the pump.